Photo by Z z on Pexels
The Road to Release 21: 6G Standardization Enters a Critical Phase
The race to define 6G is no longer a distant horizon conversation — it is happening now, in technical working groups, standards meetings, and research labs around the world. As 3GPP begins shaping Release 21, the specification package widely expected to serve as the foundational 6G standard, the industry is confronting a set of complex, interconnected decisions that will determine how next-generation networks are built, deployed, and experienced by billions of users.
Release 21 is projected to reach its early study phase conclusions in the mid-2020s, with formal specifications expected to follow later in the decade. But the groundwork being laid today — on device reference models, modulation schemes, and network migration strategies — will echo through every deployment decision operators make well into the 2030s.
New Reference Device Types Enter the Frame
One of the more significant early developments in Release 21 discussions is the introduction of new 6G reference device types that go well beyond the smartphone-centric models that have historically dominated 3GPP standards work. As the Internet of Things matures and use cases diversify, standardization bodies are grappling with the need to define performance baselines for a far broader ecosystem of connected endpoints.
Proposed reference device categories under consideration include highly mobile broadband devices optimized for extreme throughput, ultra-reliable low-latency communication (URLLC) endpoints for industrial and mission-critical applications, reduced-capability devices aimed at massive IoT deployments, and immersive extended reality (XR) terminals that demand sustained high-bandwidth, low-latency connectivity simultaneously.
This multi-device-type framework matters because it shapes antenna configurations, power consumption targets, and spectral efficiency requirements across the entire standard. Getting these reference models right is not merely an academic exercise — they directly influence chipset roadmaps, device certification programs, and ultimately, the services operators can deliver at scale.
Higher Uplink Modulation: A Game-Changer for Fixed Wireless Access
Among the most technically consequential proposals gaining traction in Release 21 discussions is the push toward higher-order uplink modulation for fixed wireless access (FWA) deployments. Current 5G NR supports up to 256-QAM in the uplink, but 6G standardization conversations are exploring 1024-QAM and potentially beyond for stationary or near-stationary FWA customer premises equipment (CPE).
The rationale is straightforward: FWA terminals, unlike handheld smartphones, can leverage larger antennas, more sophisticated signal processing hardware, and stable installation positions that make achieving the high signal-to-noise ratios required for higher-order modulation far more practical. If 1024-QAM uplink is standardized and deployable in real-world FWA scenarios, operators could see uplink throughput gains in the range of 25% compared to 256-QAM — a meaningful improvement for households and small businesses increasingly reliant on wireless broadband as a primary connectivity option.
This development is particularly relevant given the explosive growth of FWA as a broadband substitute. According to industry analysts, global FWA connections are expected to surpass 300 million by 2028, with operators in markets ranging from North America to Sub-Saharan Africa deploying FWA aggressively. Enhanced uplink modulation could be a key competitive differentiator, especially for upload-intensive applications like video conferencing, cloud backup, and content creation.
The SNR Challenge Remains Real
Despite the promise, skeptics within the standards community point out that achieving the signal quality thresholds needed for higher-order uplink modulation in outdoor, non-line-of-sight FWA scenarios remains a significant engineering challenge. Interference management, beamforming precision, and backhaul alignment all become more demanding as modulation order increases. Release 21 will need to address these realities through complementary advances in interference mitigation and link adaptation algorithms.
The Migration Question: From 5G to 6G Without Breaking the Network
Perhaps the most strategically complex issue currently unresolved in Release 21 planning is the question of migration — specifically, how operators transition their existing 5G infrastructure investments toward 6G without stranding capital or creating coverage gaps during the changeover.
Unlike the 4G-to-5G transition, which benefited from relatively clear non-standalone and standalone deployment pathways, the 5G-to-6G migration presents new complications. Many operators are still in mid-cycle 5G deployments, with significant mid-band and millimeter wave buildouts underway or planned. A 6G standard that requires wholesale spectrum re-farming or radical antenna architecture changes could impose costs that delay adoption and fragment global interoperability.
Standards discussions are reportedly exploring dual-mode network functions, backward compatibility frameworks at the core network level, and the potential for software-defined radio approaches that allow existing hardware investments to be partially reused. How these questions are resolved will have profound implications for smaller operators and emerging market carriers with more constrained capital budgets.
Industry Outlook: Convergence Ahead, But Complexity Remains
The shape of Release 21 is becoming clearer, but it is by no means settled. The decisions being made in 3GPP working groups today represent genuine technical tradeoffs with long-term commercial consequences. Vendors, operators, and device manufacturers all have strong — and sometimes competing — interests in how 6G is defined.
What is increasingly evident is that 6G will not simply be “faster 5G.” It is being designed from the ground up to accommodate a richer ecosystem of device types, support more demanding use cases across fixed and mobile broadband, and integrate artificial intelligence more deeply into the air interface itself. For the telecom industry, Release 21 is not just a standards document — it is the blueprint for the next decade of network investment.
As one industry observer aptly noted, the choices made in standardization rooms today will be etched into silicon and steel for years to come. The stakes, and the attention being paid to them, have never been higher.
